Device for use in storing a material, such as a liquid, in metal barrels

ABSTRACT

A device is used for storage and transportation of a material such as a liquid in a standard type barrel having a threaded bunghole. The device includes an impermeable flexible bag, normally made of a plastic material, of a shape and volume substantially similar to that of the barrel and intended to be inserted into the barrel through the bunghole. The flexible bag has a relatively rigid, cylindrical neck portion formed with external threads corresponding to internal threads of the barrel bunghole. After having inserted a body portion of the bag into the barrel the neck portion is tightly threaded into the barrel bunghole, the bag is filled through its neck portion and the latter closed by a lid or plug threaded into the bag neck portion. A tubular case facilitates insertion of the flexible bag through the barrel bunghole, while also serving as a package for the bag before use.

BACKGROUND OF THE INVENTION

The present invention relates to a device for use in storing a material,such as a liquid, in a metal barrel of the type having a threaded endopening or "bunghole", particularly standard barrels of the type used inthe oil industry.

Liquid waste material of a noxious or contaminant nature, such as wasteoil, chemicals, etc., is normally stored in metal barrels or drums,particularly of the standard type used in the oil industry, until it canbe disposed of by combustion or otherwise. Barrels used for such purposeare usually wellworn, having more or less severe damage and corrosionattacks that may lead to cracks. Consequently such barrels will tend toleak and cause contamination, particularly during transport, when thebarrels are often subject to rough treatment.

An attempt to solve this problem is represented by WO, A, 88/08401,which proposes a device for use in storing a material, such as a liquid,in a metal barrel having a threaded bunghole, comprising an imperviousbag of a shape and volume adapted to that of the barrel and having arelatively rigid, cylindrical neck portion adapted to be screwed intothe barrel bunghole. The cylindrical neck portion of the bag hasexternal threads mating with corresponding internal threads in thebarrel bunghole, and having internal threads mating with correspondingexternal threads of a plug. A serious drawback of this prior device isthe fact that the neck portion of the bag, when installed in a standardbarrel, protrudes relatively high above the rim of the drum, therebypreventing stacking of the barrels or barrel pallets on top of eachother, which is the usual way of storing industrial barrels of thestandard type, as used and reused in millions upon millions ofsituations throughout the world.

Finnish patent publication No. 55 814 which also relates to a plasticbag serving as a lining in a metal barrel proposes a solution to suchhigh neck problem. According to such patent, after the bag has beeninserted in the metal barrel, its flexible mouth portion is secured tothe barrel bunghole by clamping it between the latter and a deformableplastic ring that is hammered into the threaded barrel bunghole. Then aninternally threaded tubular sleeve is forced into the plastic ring andits opening closed by a plug o the like after the bag has been filled.The filled bag is apt to rupture near its clamped mouth portion and therather complex, multipart clamping and closing device is cumbersome inuse.

Also, from GB patent No. 1 392 603 it is known to furnish an apertureddrum with an internal plastic liner having a self-supporting neckpassage through the drum aperture. However, such liners are for drumshaving detachable ends which must be removed before the liner can beinserted into the drum.

No doubt the impractibility of the various known devices as describedabove is the reason why they have not found any widespread use withbarrels of the above standard type, in spite of the obvious demandwithin the field for a device to solve the above leakage problem.

SUMMARY OF THE INVENTION

The device according to the present invention is similar to that of thepreviously mentioned WO publication to the extent as defined above, butit differs from the prior art by the rigid threaded neck portion beingintegral with the bag body portion, and by the internal threadsextending at the same level as and therefore being of a smaller diameterthan the external threads.

Such device according to the present invention does not suffer from theabove discussed shortcomings of the prior devices. By arranging the neckportion internal and external threads at the same level, the bag neckportion will extend below the rim of the barrel, and by the bag neck andbody portions being integral the risk of leakage will be practicallyeliminated, even with roughly treated wellworn barrels. In addition thedevice according to the invention is surprisingly simple in use andcheap in production.

The invention is primarily developed with a view to safe storing ofwaste liquids as discussed above, but it is also very useful andbeneficial for use in storing other forms of liquid, e.g. paint, inbarrels or drums. Furthermore it may be used for other materials thanliquids, e.g. pulverulent, particulate or other bulk materials. In allcases the quality of the contents of a bag device according to theinvention, installed in a barrel, is protected against condensationwater and contamination from the barrel walls.

The invention also comprises a tubular, longitudinally split two-piececase particularly suitable for serving as a combined package for the bagand plug and a means for inserting the bag into the barrel.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in detail with reference to thedrawings in which:

FIG. 1 is a perspective view somewhat schematically illustrating theintended use of the device according to the invention;

FIG. 2 is a partial sectional view, on an enlarged scale, showingdetails of the device according to the invention;

FIG. 3 is an elevation view showing the device in a convenient conditionready for use;

FIG. 4 is a perspective view of a tubular two-piece case facilitatinginsertion of a flexible bag through a barrel spunghole while alsoserving as a package for the bag;

FIG. 5 is a cross-section through to the tubular case along lines 5--5in FIG. 4; and

FIG. 6 is a partial elevational view showing the inside of one of thecase halves.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 the numeral 2 designates a standard metal (steel) barrel of,e.g., 100 or 200 l capacity, having an internally threaded, normally 2",filling/emptying opening or "bunghole" 4 formed in the top wall thereofand surrounded by an upstanding rim 5 (FIG. 2). An impermeable, flexiblebag 6, indicated with broken lines in FIG. 1, has been inserted throughthe barrel bunghole 4. "Impermeable" as used herein means impermeable tothe material which the bag is to contain. Bag 6 has a relatively rigid,cylindric neck portion 8 integral with a bag body portion 7 (FIGS. 2 and3) and adapted to be threaded into the bunghole 4. The bag body portion7 has a shape and volume generally conforming to the internal cavity ofthe barrel, so that the walls of the bag in its expanded or filledcondition in the barrel substantially contact the internal wall surfaceof the barrel, at least the bottom wall and the major part of the sidewall. Since the bunghole 4 of such standard barrel is eccentricallylocated or offset near the peripheral side edge of the barrel the neckportion 8 of the bag 6, when the latter is intended for such standardbarrels, will be correspondingly eccentrically located near the circularcircumference of the bag in its filled condition, i.e. offset relativeto the longitudinal axis of the bag 6.

FIG. 2 shows the neck portion 8 of the bag 6 threaded into the bunghole4 and provided with an associated, threaded lid or plug 10.

The flexible bag 6 has a somewhat thickened (relative to the bag bodyportion 7) cylindrical neck portion 8 formed with external threads 12mating with the internal threads of the bunghole 4 of the standardbarrel 2 and extending about the same length. Also, the bag neck portion8 is formed with an upper flange 18 having an outer diameter equal tothat of the bunghole rim 5. When installed in the barrel 2 as explainedabove, the bag 6 can be filled with the material to be stored thereinthrough the bag neck portion 8. Owing to its particular shape (eccentricneck portion) and flexibility the bag will substantially fill the voidin the barrel, while the barrel walls form a protective casing aroundthe filled bag.

The neck portion also comprises a set of internal threads 20 permittingthe bag neck portion 8 to be closed by externally threaded lid or plug10 having a shape substantially similar to that of the plug of thestandard barrel 1 and, like the latter, having a hexagonal recess 22 fora wrench. When thus threaded into its bunghole 4 the plug 10, whichpreferably is plastic, will clamp the neck portion flange 18 of the bag6 sealingly against the bunghole rim 5 as shown in FIG. 2. As anadditional safety means, a seal-coating 16, indicated by dashed lines,may be applied over the plug 10 and the external circumference of thebunghole rim 5. Owing to its low height above the barrel top, theplugged neck portion 8 will not be exposed to mechanical damage morethan an ordinary plugged barrel void of any internal barrel. When theneck portion is completely threaded into its bunghole as shown in FIG.2, the bag will be properly angularly oriented in the barrel, i.e. suchthat the major lateral extension thereof substantially coincides withthe diameter through the bunghole 4 of the barrel 1. In addition the bagneck portion 8 could be provided with a marking (not shown) which, whenthe bag is correctly oriented, is located opposite a correspondingmarking on the barrel top.

Normally the bag 6 will be made from a relatively strong plasticsmaterial resistant to oil and chemicals, about 0.2 mm thick, typicallyvarious types of TPV, plasticized PVC or other thermoplastic elastomerscould be used. The walls of the plastic bag may be reinforced, ifdesired, e.g. by fiberglass.

In order to facilitate insertion of the empty bag 6 through the bunghole4 of the barrel, such bag may advantageously be stored and distributedin a condition in which its body portion is relatively tightly folded orrolled up in the longitudinal direction under the neck portion 8 asindicated in FIG. 3, and releasably retained in a such folded or rolledup condition by means of suitable retaining means such as tape, rubberbands or the like (not shown). Such means may be removed immediatelyprior to or when inserting the bag into its barrel, since the bag, owingto a certain "slowness" of the plastic material, still maintains itscompact condition for a time sufficient to allow its insertion throughthe bunghole. However, the retaining means need not always be removedprior to insertion of the bag, since they may be caused to release orrupture after having inserted the bag into the barrel, for example byapplying a pressure fluid such as air into the bag via an appropriatenipple (not shown) threaded into the bag neck opening. This also resultsin a complete unfolding of the bag into contact with the surroundingwalls of the barrel, such that the material to be stored can easily befilled into the thus plastic lined barrel.

However, according to an advantageous aspect of the device according tothe invention the retaining means may include a tubular, longitudinallysplit cover or case 30 as shown in FIGS. 4 through 6. Each preferablyidentical case half 30', along at least part of two longitudinal edgesthereof, is provided with means for releasable interconnection of thetwo halves, while permitting relative longitudinal displacement thereof.In the shown embodiment the interconnecting means are in the form of alip 31 and slit 32 respectively.

Advantageously one end portion (the upper one in use) of the case halves30' may be without the interconnecting means and formed with two moldedchamber halves 33, 34 adapted to receive the threaded neck portion 8 ofthe bag 6 and the plug 10 respectively, while the remaining (lower) caseportion receives the bag body portion 7. Above and below the chamberhalves 33, 34 each case half 30' is formed with a radially protrudingshoulder or stop 35 and a longitudinally extending pulling flap 36,respectively.

Preferably the case 30 is made from a transparent plastics material,such as a PET, PS or PVC thermoformable material with a wall thicknessimparting adequate rigidity to the case while also permitting a certainlateral flexibility normal to the plane of interconnection of the twocase halves.

When using the above described case 30 the bag 6 in its folded or rolledup condition is placed in one of the two case halves 30' with its rigidneck portion 8 in the chamber half 33 while a lid or plug 10 is placedin the case upper chamber half 34. Then the other, empty case half 30'is placed over the filled one and the two halves 30', 30' are joined byinserting the edge lips 31 thereof in their respective edge slits 32.The thus assembled case 30 will then form an effective package for thebag 1 with plug 10 during storage and transportation.

When bag 6 in case 30 is to be placed in a barrel 2, the tubular case 30is inserted into the barrel through bunghole 4 until the case stop 35abuts the upper surface of bunghole rim 5. Then the upper portions ofthe two casing halves 30', 30' are bent laterally apart, thus separatingtheir respective pull flaps 36 sufficiently to allow removal of plug 10from its chamber 34, whereupon one of the case halves 30' is pulledvertically up from the barrel while the other half 30' is left in thebarrel together with the bag 1. Then the other case half 30' also can bewithdrawn while the bag remains in the barrel and its neck portion 8 canbe threaded into the barrel bunghole 4 and possibly inflated aspreviously explained. Thus, the case 30 serves both as a package for thebag 1 and plug 10 and as an aid facilitating insertion of the bag intoits barrel.

Bags 6 according to the invention may be of different materialsdepending on the kind of material to be contained therein andadvantageously they may be given correspondingly different colors. Byhaving a transparent case as noted above it is an easy matter to selectthe appropriate bag for each application.

In addition to the filling/emptying opening of bunghole 4 in standardbarrels 2 of the type for which the device according to the presentinvention is primarily intended, such barrels are also provided with athreaded 1" vent 24 (FIG. 1) which in ordinary use of such barrelsnormally will be open during filling and emptying of the barrel. Barrelsof the type in question are conventionally emptied by progressivelytilting the barrel, which is a relatively cumbersome operation oftencausing spillage. Alternatively special pump means may be used.

According to an advantageous aspect of the invention the vent 24 incombination with the plastic bag 6 may be utilized to implement anextremely simple, effective and controlled mode of emptying the materialcontained in the barrel 2 lined with the plastic bag 6. Thus, the vent24 may be provided with a suitable connecting means or nipple for apressure medium such as pressurized air, as indicated at 26 in FIG. 1.Then, by pressurizing the barrel through vent 24 the liquid contents ofa filled bag therein will be forced out through the bag neck portion 8located in the barrel bunghole 4. The rate of discharge may becontrolled simply by controlling the pressure applied to the barrel 2through vent 24, resulting in a complete emptying of the barrel. Anyconvenient means may be used as the connection means 26, but aconnection means that has been found particularly suitable is aconventional, manually controlled 3/2 directional valve, such asMartonair 03040302 with appropriate adapters, etc. Alternatively thebags may be emptied by connecting a vacuum directly to the internalthreads 20 of the bag neck portion 8, with vent 24 open.

I claim:
 1. A one-piece device for use in storing a material, such as aliquid, in a metal barrel having a threaded bunghole, said devicecomprising:an impervious bag including a body portion of a shape andvolume adapted to that of the barrel, and a relatively rigid,cylindrical neck portion integral with said body portion and adapted tobe screwed into the barrel bunghole; said cylindrical neck portion ofsaid bag having external threads to mate with corresponding internalthreads in the barrel bunghole and having internal threads to mate withcorresponding external threads of a plug; and said internal threadsextending at the same level as and being of a smaller diameter than saidexternal threads.
 2. A device as claimed in claim 1, wherein saidcylindrical neck portion has a flange located axially above saidexternal and internal threads and adapted to be clamped between thebarrel rim and peripheral flange of the plug.
 3. A device as claimed inclaim 1, further comprising a tubular, longitudinally split, two-piececase adapted to contain a longitudinally folded or rolled up said bagand a plug therefore, said two case halves being relativelylongitudinally displacable in interconnected condition, said caseserving as a package for said bag and the plug and also as a means forinserting said bag into the barrel through the barrel bunghole.
 4. Adevice as claimed in claim 3, wherein said case is formed of atransparent plastic material.